Report: Obama admin. fought to keep Rosen warrant secret

5/24/13 3:31 PM EDT

Yet another development today in the case of James Rosen, the Fox News reporter who was monitored by the Justice Dept. after receiving classified information from a State Department security adviser.

According to The New Yorker's Ryan Lizza, the Obama administration fought to keep the search warrant for Rosen’s private e-mail account secret on the grounds that they might need to monitor the account for a long period of time.

"Ronald C. Machen, Jr., the U.S. Attorney who is prosecuting Stephen Jin-Woo Kim, a former State Department adviser who allegedly leaked classified information to Rosen, insisted that the reporter should not be notified of the search and seizure of his e-mails, even after a lengthy delay," Lizza writes, citing a court filing.

Machen "argued that disclosure of the search warrant would preclude the government from monitoring the account... [and] added that “some investigations are continued for many years because, while the evidence is not yet sufficient to bring charges, it is sufficient to have identified criminal subjects and/or criminal activity serious enough to justify continuation of the investigation.”